This invention relates to apparatus for stacking product such as web units and, more particularly, for accumulating substacks of web units into larger stacks while the same are traveling vertically between two vertically spaced apart horizontal paths.
A great variety of mechanisms have been employed in the past for accumulating web units such as tissues, towels, diapers, etc., into larger stacks or accumulations. Not only have these mechanisms been complex and therefore expensive, but their very complexity often led to speed limitations. Illustrative of apparatus employed for stacking web units in the past are U.S. Pat. Nos. 3,599,805 and 3,254,889.
According to the instant invention, a simplified, reliable and high-speed stacking apparatus is provided. It can be used in an environment which includes means for advancing sub-stacks of superposed web units along a horizontal path and then through a vertical path to a horizontally traveling receiving and takeaway conveyor. The instant invention brings to that environment a pair of transfer finger mechanisms which are positioned one on each side of the horizontal path, the mechanisms each carrying a plurality of L-shaped fingers with means on the mechanisms for moving the fingers thereof through a generally obround orbit intersecting the horizontal path slightly inwardly of the sides thereof and serving to define the vertical path of accumulation.
While the rotary counting-stacking and accumulating mechanism is illustrated in combination with a converting machine that delivers substacks or a plurality of stacked sheets to the mechanism, it should be understood because of the advantageous arrangement of the parts, particularly the rotary fingers, the invention can also be arranged to receive substacks comprising a plurality of sheets or single sheets that are to be accumulated into a plurality of webs, i.e., a substack. In any case, the substack or plurality of webs rests upon each pair of coacting and oppositely extending support fingers. This is especially advantageous when the rotary count-stacking and accumulating mechanism is driven by intermittent means, for example, and indexing drive. In any event, the invention provides a much faster and more versatile operation than web segment delivery apparatus such as seen in co-owned U.S. Pat. No. 3,498,600.
Other attributes, advantages and objects of the invention may be seen in the details of the ensuing description.